JP2011107039A - Device for measuring terminal contact pressure and pressure measurement probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure contact pressure without receiving restriction on the size of a female terminal. <P>SOLUTION: In a device for measuring the contact pressure by inserting a probe 40 for measuring pressure on the female terminal 10 having an elastic contact piece 14, the probe 40 includes a pair of measuring arms 41, 42 connecting ends, and a strain gage 55 put at a connection end 52 of both the measuring arms 41, 42. One measuring arm 42 is brought into contact with the elastic contact piece 14, and the other measuring arm 41 is brought into contact with a sandwiched face 16 arranged to oppose the elastic contact piece 14 in the female terminal 10. The rigidity of one measuring arm 42 is set high as compared with that of the other measuring arm 41, and the other measuring arm 41 arranges a projection 50 abutting on the sandwiched face 16 at two parts positioned at both sides of a length direction for a contact point 48 to the elastic contact piece 14 of one measuring arm 42. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for measuring a contact pressure of an elastic contact piece at a female terminal and a pressure measuring probe used in the apparatus.

The female terminal has, for example, a shape in which an elastic contact piece is provided in a connecting portion having a rectangular tube shape, and the tab of the mating male terminal inserted into the connecting portion is connected to the elastic contact piece and the opposing wall surface in the connecting portion. Therefore, the elastic contact piece is required to have a predetermined contact pressure in order to ensure reliable conduction between the male and female terminals.
Therefore, conventionally, as described in Patent Document 1, as a method for measuring contact pressure, a measuring tool having a piezoelectric element portion is provided, and the piezoelectric element portion is inserted into a connection portion of a female terminal, so that the piezoelectric element portion is provided. There is known a method in which a contact pressure is measured based on a detected value of a pressure change applied to the pressure.

JP 2007-149517 A

However, in the apparatus using the measuring tool having the piezoelectric element portion described above, the thickness of the piezoelectric element portion that is actually inserted into the connecting portion of the female terminal is required to be about 2 mm, while the female terminal gradually increases. Many female terminals that cannot be inserted, that is, cannot be applied with a conventional measuring tool have appeared in the trend of downsizing, and a new contact pressure measuring device that can be applied to a small female terminal has been desired.
The present invention has been completed based on the above circumstances, and an object of the present invention is to enable accurate measurement of contact pressure without being restricted by the size of the female terminal.

  The present invention is a terminal contact pressure measuring device that inserts a pressure measuring probe into a female terminal having an elastic contact piece, and measures the pressure acting from the elastic contact piece by the pressure measuring probe, the pressure measuring probe being , A pair of measurement arms connected to each other, and a strain gauge provided at a connection end of the two measurement arms, one of the pair of measurement arms is the elastic contact piece, the other The measurement arms of the female terminals are in contact with opposing wall surfaces of the female terminals that are opposed to the elastic contact pieces, and the one measurement arm is set to have higher rigidity than the other measurement arm. In addition, the other measurement arm is provided on the opposite wall surface at two positions located on both sides in the length direction with respect to the contact point of the one measurement arm with the elastic contact piece. Contact protrusion has a feature where the is provided.

  Further, a pressure measurement probe that is inserted into a female terminal having an elastic contact piece and measures a pressure received from the elastic contact piece, a pair of measurement arms having ends connected to each other, and a connection between the two measurement arms A strain gauge provided at an end, and one of the pair of measurement arms is provided with one measurement arm facing the elastic contact piece and the other measurement arm is provided facing the elastic contact piece of the female terminal The one measurement arm is set to be higher in rigidity than the other measurement arm, and the other measurement arm has the elasticity of the one measurement arm. It is characterized in that protrusions that come into contact with the opposing wall surface are provided at two positions located on both sides in the length direction with respect to the contact point to the contact piece.

  The contact pressure is measured as follows. When the pressure measurement probe is inserted into the female terminal while elastically displacing the elastic contact piece, the pair of measurement arms are elastically pinched between the opposing wall surfaces by the restoring elasticity of the elastic contact piece, and the distance between the two measurement arms Accordingly, a strain (elongation) is generated on the surfaces of the connecting ends of both measurement arms, and the strain amount is taken out as an electric signal value by a strain gauge provided there, and the contact pressure is measured based on the strain value.

  Here, in such a female terminal, the opposing wall surface facing the elastic contact piece is not always formed flat, and there may be some unevenness. In this case, the other measurement arm hits the protruding part of the opposite wall surface, but the position where this protruding part hits varies, and if it is displaced in the front-rear direction with respect to the position where the elastic contact piece hits one measuring arm, it will be elastic Even if the restoring elasticity of the contact piece is the same, the amount by which the distance between the two measurement arms is narrowed slightly changes, and as a result, the distortion of the connecting end also changes, so that an accurate contact pressure cannot be measured.

  On the other hand, it was considered that a protrusion was previously formed at a predetermined position of the other measurement arm to determine the position applied to the opposing wall surface, but the elastic contact piece on the opposite side was also bent. The position where it hits one measurement arm may vary due to an error, etc. Even if the position where it hits the opposite wall surface of the other measurement arm is fixed, the distance between the two measurement arms is similarly reduced. It was found that the measurement of contact pressure was inaccurate due to errors in quantity.

  Therefore, in the present invention, regarding the pressure measurement probe, one measurement arm that contacts the elastic contact piece is set to be higher in rigidity than the other measurement arm, and the elasticity of one measurement arm with respect to the other measurement arm. The structure which the protrusion part contact | abutted to an opposing wall surface was provided in two places located in the both sides of the length direction with respect to the contact point to a contact piece is employ | adopted.

  In such a configuration, when both measuring arms are inserted between the elastic contact piece and the opposing wall surface, the other measuring arm is supported at two points with respect to the opposing wall surface, and is received in a stable posture. One measurement arm is pushed closer to the other measurement arm, but this one measurement arm has high rigidity and there is no possibility of deformation, so the elastic contact piece in one measurement arm As long as the position where the contact is pressed is between the two support points of the other measurement arm, the amount by which the distance between the two measurement arms is reduced is constant corresponding to the restoring elasticity of the elastic contact piece, and the connecting end The contact pressure can be accurately measured by keeping the distortion of the pressure constant.

  That is, according to the present invention, since the pair of measurement arms in the pressure measurement probe is inserted into the female terminal, the present invention can be applied to a small female terminal and there is some molding error in the female terminal. Even so, the contact pressure can always be accurately measured.

Furthermore, it is good also as the following structures.
(1) On the opposite end side of the pair of measurement arms of the pressure measurement probe from the connection end on which the strain gauge is provided, a coupling portion that couples the ends of the measurement arms is provided. Yes. By combining the pair of measurement arms, the rigidity can be increased. As a result, the insertion portions of both measurement arms can be made thinner, which is more effective when applied to a small female terminal.

  (2) The coupling portion is provided on the distal end side in the insertion direction of the pressure measurement probe, and is formed in a tapered shape. Since the tip ends of the pair of measurement arms are combined and tapered to function as a guide, the insertion operation with respect to the female terminal can be performed smoothly.

  According to the present invention, the contact pressure can be accurately measured without being restricted by the size of the female terminal.

The partially cutaway side view which shows schematic structure of the measuring apparatus which concerns on one Embodiment of this invention Side view of pressure measurement probe Partially cutaway side view showing the state before the probe is inserted into the female terminal Partially cutaway side view showing the state after insertion The enlarged part

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 schematically shows the entire structure of a terminal contact pressure measuring device. A pressure measuring probe 40 (hereinafter simply referred to as a probe 40) is mounted on a probe mounting base 30, while facing the probe mounting table 30. On the arranged terminal mounting base 20, the female terminal 10 to be measured is installed so as to be able to advance and retract at a position facing the probe 40.

As shown in FIG. 3, the female terminal 10 of the present embodiment has a shape in which barrels 12 and 13 that are caulked and crimped to the end of the electric wire are provided behind the connection portion 11 having a substantially rectangular tube shape, An elastic contact piece 14 is provided in the connection portion 11. The elastic contact piece 14 is formed by folding a tongue piece extending from the tip of the bottom plate 11A so that the folded end side is formed in a mountain shape, and a contact point 15 is provided on the top thereof, and a base end portion connected to the bottom plate 11A is provided. The folding end side can be elastically displaced in the vertical direction as a fulcrum.
On the other hand, a clamping surface 16 (corresponding to the opposing wall surface of the present invention) is formed in the ceiling plate 11 </ b> B of the connecting portion 11 at least in a region corresponding to the upper side of the elastic contact piece 14.

  With respect to the female terminal 10, a tab of a male terminal (not shown) is inserted into the connection portion 11 while elastically displacing the elastic contact piece 14 from the opening 17 on the front surface, and the tab is moved by the restoring elasticity of the elastic contact piece 14. By electrically pinching with the clamping surface 16, electrical connection between the female terminal 10 and the mating male terminal is achieved.

A movable body 21 is movably mounted on the terminal mounting base 20 along the guide 22 in the left-right direction in the figure, and is screwed onto a screw rod 24 that is driven to rotate in both forward and reverse directions around the axis by a servo motor 23. ing. On the other hand, the terminal holder 25 is detachably attached to the front end side of the movable body 21, and the female terminal 10 is supported on the holder 25 with both front and rear ends and is provided at the rear end. By fixing the carrier 18 with a screw 26, the connecting portion 11 is fixed in a horizontal posture in which the connecting portion 11 is directly opposed to the probe mounting base 30.
Then, by driving the servo motor 23 in both forward and reverse directions, the female terminal 10 is driven forward and backward with a stroke of, for example, 30 mm toward the probe mounting base 30. When the female terminal 10 moves to the advance position, the insertion portion 43 of the probe 40 attached to the probe mounting base 30 is set to enter a predetermined dimension into the connection portion 11 of the female terminal 10, as will be described in detail later. ing.

A mounting portion 31 is set at a position facing the female terminal 10 on the probe mounting base 30, and the probe 40 is mounted on the mounting portion 31.
The probe 40 is formed by cutting a metal block or the like, and as shown in FIG. 2, a pair of upper and lower measurement arms 41 and 42 are arranged with a predetermined gap therebetween, and the distal ends and the proximal ends thereof are arranged. And the overall shape is a flat block in the width direction (front and back direction of the paper), and the front side of less than 30% of the total length is thin, and the remaining rear side is 10 times It has a stepped shape with the above thickness. The rear side of the thick wall is also about three times wider than the front side in terms of width.

  More specifically, a further about 2/3 region on the distal end side of the thin front portion of the probe 40 is formed following the shape of the tab of the mating male terminal and is inserted into the connection portion 11 of the female terminal 10. This is an insertion portion 43. In the present embodiment, the thickness t of the insertion portion 43 is set to 0.64 mm, for example, and the insertion portion 43 elastically displaces the elastic contact piece 14 in the measurement process described later, and the connection portion of the female terminal 10. As shown in FIG. 4, when the regular depth is inserted into the head 11, the tip thereof reaches about half of the depth of the connecting portion 11, in other words, the depth beyond the folded end of the elastic contact piece 14. . The thick rear portion of the probe 40 functions as the amplifying unit 44.

As described above, the probe 40 is divided into the upper measurement arm 41 (corresponding to the other measurement arm of the present invention) and the lower measurement arm 42 (corresponding to one measurement arm of the present invention) with a predetermined gap. However, an extremely small gap (for example, 0.02 mm) is formed at the center in the thickness direction from the vicinity of the distal end of the insertion portion 43 to the vicinity of the central portion in the length direction of the amplification portion 44. On the other hand, a large gap (for example, 1.2 mm) 46 is continuously formed in a region in the vicinity of the rear edge from the central portion in the length direction of the amplifying portion 44. However, the large gap 46 is formed at a position offset upward from the center in the thickness direction.
Thereby, the thickness of the rear side of the amplifying unit 44 in the lower measurement arm 42 is made larger than that of the rear side of the amplifying unit 44 in the upper measuring arm 41. As a result, the lower measuring arm 42 is The rigidity is set to be higher than 41.

The distal end portion 43A (corresponding to the coupling portion of the present invention) of the insertion portion 43 of the probe 40 is formed in a tapered shape that tapers in the thickness direction and the lateral width direction.
As described above, when the insertion portion 43 of the probe 40 is inserted into the connection portion 11 of the female terminal 10 in a normal amount, the contact 15 of the elastic contact piece 14 is connected to the lower measurement arm 42 as shown in detail in FIG. The insertion portion 43 comes into contact with a position slightly behind the base of the tapered surface on the lower surface. Hereinafter, this position is referred to as a contact point 48.
Further, at two positions spaced apart by a predetermined dimension on the upper surface of the insertion portion 43 of the upper measurement arm 41 with a fixed dimension in the front and rear directions, the ridges 50 (same height of the present invention) having a gentle cross-sectional chevron shape. (Corresponding to the protrusion) is formed over the entire width. The dimension separated from the contact point 48 before or after is, for example, about 0.25 mm.

In addition, a portion of the rear edge of the amplifying unit 44 of the probe 40 corresponding to the rear of the larger gap 46 becomes a connection end 52 that connects the base end portions of the upper measurement arm 41 and the lower measurement arm 42. However, a strain gauge 55 is attached to the surface of the connecting end 52. From the strain gauge 55, an output voltage proportional to the strain amount (elongation amount) of the attached surface can be obtained.
Note that the front and rear mounting holes 53 are opened in the amplifying unit 44 of the lower measurement arm 42.

As shown in FIG. 1, such a probe 40 is applied to the mounting portion 31 of the probe mounting base 30 in a posture in which the insertion portion 43 is coaxially opposed to the female terminal 10, and the bolt 33 is passed through the mounting hole 53. It is fixed by tightening. At this time, it is desirable that the probe 40 be attached so as to be somewhat movable. This is to cope with a case where the axes of the insertion portion 43 and the female terminal 10 are shifted.
When the female terminal 10 arranged on the terminal mount 20 side advances to the front end position of the stroke, the insertion portion 43 of the probe 40 is inserted into the connection portion 11 of the female terminal 10 by a normal amount. Yes.

Subsequently, a procedure for measuring the contact pressure will be described.
As shown in FIG. 1, a female terminal 10 to be measured is set on a terminal mounting base 20 via a holder 25. When the servo motor 23 is driven from this state, the movable body 21 moves forward. Accordingly, the insertion portion 43 of the probe 40 moves forward into the connection portion 11 of the female terminal 10 as shown by the arrow in FIG. Is inserted from. The probe 40 is pushed in such a way that it is split between the sandwiching surface 16 of the ceiling plate 11B while elastically displacing the elastic contact piece 14. When the movable body 21 stops at the advanced position, the insertion portion 43 of the probe 40 is inserted into the connection portion 11 in a normal amount as shown in FIGS. 4 and 5. At that time, due to the action of the restoring elasticity of the elastic contact piece 14, the lower measurement arm 42 is pushed up in a state where the upper measurement arm 41 is received with the two front and rear ridges 50 applied to the clamping surface 16, and both measurement arms 41, 42 is narrowed and amplified in the amplifying unit 44. Along with this, distortion (elongation) occurs on the surface of the connecting end 52 of both measurement arms 41 and 42, and the amount of distortion is taken out as a voltage value by the strain gauge 55. Based on this, the contact pressure is measured.

  By the way, in such a female terminal 10, the sandwiching surface 16 of the ceiling facing the elastic contact piece 14 is not always formed flat, and there may be some unevenness. If the upper measurement arm 41 is not provided with the protrusion 50, the upper surface of the upper measurement arm 41 will hit the protruding portion of the clamping surface 16. However, the position where the protruding portion hits varies, and the lower measurement arm 42 If the elastic contact piece 14 is displaced in the front-rear direction with respect to the contact point 48, even if the elastic elasticity of the elastic contact piece 14 is the same, the amount by which the distance between the measurement arms 41 and 42 is narrowly changed. As a result, the distortion of the connecting end 52 also changes, and an accurate contact pressure cannot be measured.

  On the other hand, it has been considered that a protrusion is formed in advance at a predetermined position (one place) of the upper measurement arm 41 to determine a position to be applied to the sandwiching surface 16. Also for the contact piece 14, there is a possibility that the contact point 48 that contacts the lower measurement arm 42 may vary due to an error in bending, and even if the position that contacts the clamping surface 16 in the upper measurement arm 41 is determined, Similarly, it has been found that there is an error in the amount by which the distance between the measurement arms 41 and 42 can be reduced, and that the measurement of the contact pressure is inaccurate.

  Therefore, in the present embodiment, regarding the pressure measurement probe 40, the lower measurement arm 42 that contacts the elastic contact piece 14 is set to have higher rigidity than the upper measurement arm 41, and the lower measurement arm 41 is lower than the upper measurement arm 41. A configuration is adopted in which protrusions 50 that abut on the clamping surface 16 are provided at two locations spaced on both sides in the length direction across the contact point 48 of the elastic contact piece 42 of 42.

  According to such a configuration, when the two measurement arms 41, 42 constituting the insertion portion 43 of the probe 40 are inserted between the elastic contact piece 14 and the clamping surface 16, the upper measurement arm 41 is against the clamping surface 16. It is received in a stable posture by being supported at two points, and the lower measurement arm 42 is pushed so as to approach the upper measurement arm 41, but the lower measurement arm 42 has high rigidity and itself Since there is no possibility of deformation, as long as the contact point 48 to which the elastic contact piece 14 hits and is pressed in the lower measurement arm 42 is between the two protrusions 50 (support points) of the upper measurement arm 41, both measurements are performed. The amount by which the distance between the arms 41 and 42 is reduced becomes a constant amount corresponding to the restoring elasticity of the elastic contact piece 14, and the distortion of the connecting end 52 is also kept constant, so that the contact pressure can be accurately measured.

That is, according to the present embodiment, what is inserted into the connection portion 11 of the female terminal 10 is the insertion portion 43 constituted by the thin portions of the pair of measurement arms 41 and 42 in the probe 40, so that the small female terminal is provided. 10, even if there is some molding error in the female terminal 10, the contact pressure can always be accurately measured.
In particular, the thin portions of the upper and lower measurement arms 41 and 42 constituting the insertion portion 43 can be made rigid by joining the tips to each other. As a result, the insertion portion 43 can be made thinner and smaller. This is more effective when applied to the female terminal 10.
Further, since the distal end portion of the insertion portion 43 has a tapered shape, the insertion operation of the female terminal 10 with respect to the connection portion 11 can be performed more smoothly by functioning as a guide.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the distal end portion of the probe insertion portion is tapered, but it may be kept straight.
(2) The so-called open structure may be used without connecting the distal ends in the insertion direction of both measurement arms constituting the insertion portion.
(3) In the above embodiment, the strain gauges are attached to the connecting ends of the base ends of both measurement arms. However, depending on the shape and size of the probe insertion part, the ends of both measurement arms may be connected to each other. A strain gauge may be attached to the part.

(4) Regarding the probe, the thickness of the insertion portion exemplified in the above embodiment and the dimensions of the gap provided in the insertion portion are merely examples, and conditions such as the shape and size of the female terminal to be measured Can be appropriately selected according to the above.
(5) The female terminal to be measured is not limited to the shape exemplified in the above embodiment, and the main point is a cylindrical connection, such as a two-point support form in which the folded end of the elastic contact piece hits the bottom plate. The present invention can be widely applied to all female terminals having a structure having an elastic contact piece in the portion.

DESCRIPTION OF SYMBOLS 10 ... Female terminal 11 ... Connection part 14 ... Elastic contact piece 15 ... Contact 16 ... Nipping surface (opposite wall surface)
40 ... Pressure measurement probe 41 ... Upper measurement arm (the other measurement arm)
42 ... Lower measurement arm (one measurement arm)
43 ... Insertion part 43A ... Tip part (of the insertion part 43) (joint part)
48 ... contact point 50 ... ridge (projection)
52 ... Connection end 55 ... Strain gauge

Claims (6)

A terminal contact pressure measuring device for inserting a pressure measuring probe into a female terminal provided with an elastic contact piece, and measuring a pressure acting from the elastic contact piece by the pressure measuring probe,
The pressure measurement probe includes a pair of measurement arms whose ends are connected to each other and a strain gauge provided at a connection end of the both measurement arms, and one of the pair of measurement arms is elastic. The contact piece, the other measuring arm is in contact with the opposing wall surface provided facing the elastic contact piece in the female terminal,
The one measurement arm is set to be higher in rigidity than the other measurement arm, and
The other measurement arm is provided with protrusions that contact the opposing wall surface at two positions located on both sides in the length direction with respect to the contact point of the one measurement arm with the elastic contact piece. Terminal contact pressure measuring device. On the end side of the pair of measurement arms of the pressure measurement probe opposite to the connection end where the strain gauge is provided, a coupling portion that couples the ends of the two measurement arms is provided. The terminal contact pressure measuring device according to claim 1, wherein: The terminal contact pressure measuring device according to claim 2, wherein the coupling portion is provided on a distal end side in the insertion direction of the pressure measuring probe and is formed in a tapered shape. A pressure measurement probe that is inserted into a female terminal having an elastic contact piece and measures the pressure received from the elastic contact piece,
A pair of measurement arms connected to each other; and a strain gauge provided at the connection ends of the two measurement arms, wherein one measurement arm of the pair of measurement arms is connected to the elastic contact piece, and the other The measurement arm is adapted to contact with the opposing wall surface provided facing the elastic contact piece in the female terminal,
The one measurement arm is set to be higher in rigidity than the other measurement arm, and
The other measurement arm is provided with protrusions that contact the opposing wall surface at two positions located on both sides in the length direction with respect to the contact point of the one measurement arm with the elastic contact piece. And a pressure measuring probe. The coupling portion in which the ends of the two measurement arms are coupled to each other is provided on the end of the pair of measurement arms opposite to the connection end provided with the strain gauge. 4. The pressure measuring probe according to 4. 6. The pressure measurement probe according to claim 5, wherein the coupling portion is provided on a distal end side in the insertion direction of the pressure measurement probe and is formed in a tapered shape.

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